Ecological problems are nowadays of general concern. In particular, in Italy much attention is being paid to the problem of algal blooms in the Adriatic Sea and this has led also to an increase of interest in mathematical ecology at all levels, from high school teaching to advanced research. The logistic differential equation, dealt with in the next section, is a classical but still useful model for describing the dynamics of a one-species population in and environment with limited resources. For example, the data in Table 1 and Figure 1 represent the time evolution of an algal sample taken in the Adriatic Sea and do seem to follow a logistic curve. We will explore the problem of fitting, in the least-squares sense, a logistic curve (i.e., the solution to the logistic equation) to such a set of measured data.